Wounds to the human anatomy may result from interventional, minimally-invasive and/or intraoperative surgical procedures, acts, diseases, and/or underlying conditions. For example, iatrogenic wounds generally are formed during surgery for treating sinusitis, and due to the complicated topology of the sinuses, may take extended periods to heal. In addition, certain portions of the human anatomy are prone to the development of post-operative lesions, which often require treatment via subsequent surgical intervention.
Sinusitis is inflammation of the paranasal sinuses generally due to infection, allergies, or autoimmune issues. Chronic sinusitis affects persons of all age groups and is one of the more prevalent chronic diseases in the United States, affecting 37 million Americans. Chronic sinusitis may persist for 12 weeks or longer. Surgery, although minimally invasive, is generally reserved for acute/intermittent rhinosinusitis and chronic/persistent rhinosinusitis unresponsive to conservative medical treatment or where there are complications associated with those conditions. Functional endoscopic sinus surgery (FESS) of the diseased sinus mucosa has been proposed to enable ventilation through the natural ostia and restore mucociliary clearance using a minimally invasive endoscopic technique. Although FESS has proven to be an effective procedure in treating chronic sinusitis, the outcome of the surgery can become significantly complicated by operative pathologies, including delayed wound healing, stenosis of the sinus passageways (˜in 20-30% of cases), adhesions, and the formation of polyps. Various mechanical means such as nasal stents and packings have been developed to treat such wounds; however, experience has shown that these methods do not provide an effective way of addressing the complications.
Pharmaceutical treatment of iatrogenic wounds with therapeutic agents such as steroids has been shown to reduce postoperative complications. However, there does not exist in the prior art an effective manner for delivering appropriate dosages of therapeutic agents over a desired timeframe within the sinus cavities.
Balloon sinus dilation is a relatively new technique for treating chronic sinusitis by opening blocked passages with balloon inflation. While more limited in application than FESS, this modality may become the treatment of choice for limited or moderate sinus disease. Accordingly, it would be desirable to provide an effective device for delivering a therapeutic agent to sinus tissue over a period of time following balloon sinus dilation.
U.S. Patent Application Publication Nos. 2011/0071498 and 2011/0071499 to Hakimimehr, assigned to the assignee of the present invention, the contents of both of which are hereby incorporated by reference, describe devices having a free-standing film of solid fibrinogen, and optionally solid thrombin, configured in the form a thin sheet. The device may be configured to release a therapeutic agent over time.
It would be desirable to provide a device, such as described in the foregoing Hakimimehr publications, that permits the release of different therapeutic agents over the same temporal profiles and/or different therapeutic agents over different temporal profiles.